This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A116160 #9 Jul 21 2021 08:35:18 %S A116160 4,94,210,294,994,5880,9994,52888,99994,127044,414180,999994,8264470, %T A116160 9999994,12456750,41868508,99999994,112670544,441341880,468144040, %U A116160 669421494,702338994,715976338,750005718,960645294,999999994 %N A116160 Numbers k such that k concatenated with itself gives the product of two numbers which differ by 7. %Y A116160 Cf. A020338, A116152, A116159, A116161, A116167, A116291. %K A116160 nonn,base %O A116160 1,1 %A A116160 _Giovanni Resta_, Feb 06 2006